A control circuit for adaptive noise margin control for a constant on time (COT) converter comprises an input reference terminal, amplifier, first switch device, voltage divider, trigger circuit, and output reference terminal. The amplifier has an input terminal coupled to the input reference terminal receiving a reference voltage signal. The first switch device has a control terminal coupled to an output of the amplifier, a first conduction terminal for receiving a voltage source signal, and a second conduction terminal. The voltage divider is coupled to the second conduction terminal and another input terminal of the amplifier. The trigger circuit, coupled to the voltage divider, is for triggering voltage change of a modified reference voltage signal selectively according to a high-side control signal of the COT converter. The output reference terminal coupled to the second conduction terminal outputs the modified reference voltage signal.
Legal claims defining the scope of protection, as filed with the USPTO.
4. The control circuit according to claim 3, wherein the compensation current source is used for receiving the high-side control signal and outputting a variable current according to a measure of OFF period as a percentage of a total period for the high-side control signal.
5. The control circuit according to claim 4, wherein when the high-side control signal is asserted, the compensation switch device turns on such that the variable current output by the compensation current source flows into the voltage divider.
7. The control circuit according to claim 6, wherein the duty cycle estimation circuit includes a low pass filter for receiving the high-side control signal and generating the voltage signal indicating the duty cycle of the high-side control signal.
8. The control circuit according to claim 6, wherein the compensation controller includes a voltage to current converter for outputting the variable current according to the scaled-down voltage signal.
11. The control circuit according to claim 9, wherein the output reference terminal is used for being coupled to an input of a comparator of the COT converter.
12. The control circuit according to claim 9, wherein each of the plurality of compensation current sources is used for outputting a corresponding constant current.
13. The control circuit according to claim 9, wherein the control circuit further comprises a compensation resistor coupled between the second conduction terminal and the output reference terminal.
14. The control circuit according to claim 9, wherein when the corresponding compensation control signal is asserted, the corresponding compensation switch device turns on such that the corresponding current source sinks current from the current path.
16. The control circuit according to claim 15, wherein the duty cycle estimation circuit includes a low pass filter for receiving the high-side control signal and generating the voltage signal indicating the duty cycle of the high-side control signal.
17. The control circuit according to claim 15, wherein the compensation controller includes a plurality of comparators for output the plurality of compensation control signals according to the scaled-down voltage signal and respective compensation reference signals.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
August 22, 2022
June 18, 2024
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.